Fluid-pressure brake.



W. V. TURNER. FLUID PRESSURE BRAKE. APPLICATION FILED NOV. 2, 1909.

Patented May 28, 1912.

2 SHEETS-SHEET l.

wi-rNEssEs COLUMBIA PMNOQRAPH co.,wAsH1NGTON. D. c.

W. V. TURNER.

FLUID PRESSURE BRAKE. APPLICATION FILED NOV. 2', 1909.

' v Patented May 28, 1912.

2 SHEETS-SHEET 2.

WITNESSES COLUMBIA uNobRAPn C0,,WASHINGTON, n. c.

U ETE SE WALTER V. TURNER, OF EDGEWOOD, PENNSYLVANIA, ASSIGNOR TO THE WESTING- HOUSE AIR BRAKE COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

FLUID-PRES$URE BRAKE.

To all whom, it may concern:

Be it known that I, WALTER V. TURNER, a

citizen of the United States, residing at Edgewood, in the county of Allegheny and State of Pennsylvania, have invented new and useful Improvements in Fluid-Pressure Brakes, of which the following is a specification. This invention relates to automatic fluid pressure brakes, and more particularly to the engineers brake valve for controlling the admission of fluid under pressure to and its release from the train pipe.

With the growing necessity for operating trains at the greatest possible frequency and speed in some classes of railway service, notably electric traction service in large cities, the time element in stopping and starting the trains has become of increasing importance and it is therefore highly desirable to provide every facility for quickly stopping the trains and to this my invention is more particularly directed.

It is well known that use of the equalizing piston and train pipe discharge valve is quite'necessary in long trains in order to provide against the release of the brakes on the head end of the train by the surging forward of the air in the train pipe from the rear end when the brake valve is moved from application to lap position. But on short trains a mechanism of this character for controlling the discharge of air from the train pipe usually operates slowly as compared with a direct port through which to discharge air from the train pipe and consequently some time might be saved by employing a direct train pipe exhaust port on short trains.

One object of my invention is to provide an engineers brake valve having both an equalizing discharge valve mechanism and a direct exhaust. port for discharging air from the train pipe in making service applications of the brakes so that in operating short trainsthe benefit of a direct exhaust portis obtained while for long trains the operation of the equalizing discharge valve mechanism is available.

It has also been proposed to employ an additional reducing reservoir or chamber into which air is vented from the equalizing Specification of Letters Patent.

Application filed November 2, 1909.

Patented May 28, 1912.

Serial No. 525,871.

the equalizing reservoir pressure and conse quently the train pipe pressure in making service applications of the brakes and also in order that the train pipe pressure may not be reduced to such an, extent that the graduated release of the brakes is rendered difficult. If such a reservoir is employed, it will be seen that in using a direct train pipe discharge port, the train pipe may continue to be reduced through the direct port after the equalizing reservoir has equalized into the reducing reservoir and thus interfere with the function of limiting the reduction in train pipe pressure.

Another object of my invention therefore consists in providing means for closing the direct discharge port upon equalization of the equalizing reservoir pressure into the reducing reservoir.

In the accompanying drawings, Figure 1 is a vertical section of an engineers brake valve with my invention applied thereto; Fig. 2 a plan view 'of an engineers brake valve constructed according to my invention with the rotary valve portion removed and showing the device for controlling the direct train pipe exhaust in section; Fig. 3 a similar view showing a somewhat modified construction for controlling the direct train pipe exhaust port; Figs. 4 to 7 inclusive are diagrammatic views illustrating the relative positions of the brake valve in release, lap, service application and emergency application positions respectively; and Fig.8 a face view of the rotary valve of the brake valve showing the relative arrangement of ports and passages therein.

As shown in the drawings, an engineers brake valve may be provided comprising a casing 1 containinga rotary valve 2 operated by a handle 3 and an equalizing dis charge valve mechanism having a piston 4E and a valve 6 operated by the piston 4 for controlling the release of air from the train pipe passage 7 to exhaust port 8. The chamber 9 on one side of the piston 42 is connected by a pipe 10 to an equalizing reservoir 11 and the chamber 12 on the opposite side of the piston is open to the train pipe.

All of the above may be of the usual standard construction and in addition a reducing reservoir 13 is provided having a pipe 14: leading to the seat of the rotary valve 2, the rotary valve being provided with a cavity 15 adapted to connect the pipe 14 with a passage 16, in open communication with the equalizing reservoir, in service application position of the brake valve.

As shown in Fig. 2, the rotary valve seat is provided with a central exhaust port 17, train pipe port 18, port 19 leading to the equalizing reservoir pipe 10, port 20 leading to the reducing reservoir bipe 1%, and a direct exhaust port 21 opening to a pas sage 22.

In operation, it it is desired to make a service application ot the b tlh'OS the brake valve handle is turned to service application position and as shown in Fig. 6, cavity 15 in the rotary valve then connects the reducing reservoir port 20 with the equal izing reservoir port 19, so that the pressure inthe equalizing reservoir and in the chamber 9 above the equalizing piston t is reduced to the desired degree up to the point at which the equalizing reservoir pressure fully equalizes into the reducing reservoir. In the same position the direct exhaust port 21 is connected by a cavity 23 in the rotary valve having port openings 24: and 25 with the train pipe port 18, so that fluid is also discharged from the train pipe through the passage 22. This passage 22 may open directly to the atmosphere but where a reducing reservoir is employed I provide means for closing this discharge passage upon equalization of the equalizing reservoir into the reducing reservoir. As shown in Fig. 2 this means may consist of a piston 26, subject on one side to the pressure in the passage 22 and a light spring 27 and on the opposite side to the pressure of the reducing reservoir 13 to which it is connected through a passage 28. The piston 26 operates a valve 29 for controlling communication from passage 22 to a passage 30 opening to the central exhaust port 17 When there is no fluid pressure on either side of the piston 26 the spring 27 maintains the piston and valve 29 in the open position. Upon turning the brake valve to service application position, fluid from the train pipe flows through passage 22 out to the atmosphere through passage 30 and also acts on one side of the piston 26 to maintain same in open position. As the pressure in the reducing reservoir is increased by flow from the equalizing reservoir a point is reached at which the pressure is sufficient to overcome the pressure flowing from the train pipe through the direct exhaust port and the pressure of the spring 27 and the piston is then moved to close the valve 29 thus preventing the further direct discharge of fluid from the train pipe.

In Fig. 3 a slightly modified construct-ion for the same purpose is shown comprising i a double seating piston 31 having the passage 28 from the reducing reservoir opening to one side thereof and passage 22 leading to ports 32 in bushing 33. Exhaust passage 30 opens to the chamber on the opposite side of piston 31 and the piston is provided with a cylindrical valve piston adapted to control the ports 32. A spring 34 tends to maintain the piston in position shown with the ports 32 open. In operation, upon turnlng the brake valve to service application position, air is admitted to passage 22 from the train pipe and passing through the open ports 32- is discharged to the atmosphere through the passage 30. Upon the pressure in the reducing reservoir becoming substantially equal to the equalizing reservoir pressure, the same flowing through passage 28 to the piston 31 lifts same from its seat and operates to close the ports 32, cutting ofl the further escape of air from the train pipe. It will be noted that only a reduced area of the piston 31 is normally exposed to the reducing reservoir that fluid in the reducing reservoir and on the piston 26 is vented to the atmosphere, and successlve service applications of the brakes may then be made as desired.

In release posi tion the usual connections are made for recharging the train pipe and the equalizing reservoir, the cavity 38 having the through port 39 registering with the equalizing port 19 and the through port 40 in the rotary valve 2registering with the train pipe port 18.

An emergency application of the brakes may be made by turning the brake valve to emergency position as shown in Fig. 7', in which the large exhaust cavity 41 registers with the train pipe port 18, so as to suddenly reduce the train pipe pressure;

It will now be seen that by means'of the above described construction a direct train pipe dischargeport is connected to the train pipe in service application position and thus the train pipe pressure is promptly reduced, while uponmoving the brake valve to lap position anysurge of air from the rear end of the train to the head end is discharged by the usual action of the equalizing piston and valve. V

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is y r 1 In a brake valve, the combination with a valve mechanism governed by the opposing pressures of thetrain pipe and a chamber for controlling the release of fluid from the train pipe, of means for venting air from said chamber and directly from the train pipe in one position of the brake valve.

2. An engineers brake valve device comprising a chamber, a valve mechanism subject to the opposing pressures of the train pipe and said chamber for controlling the release of fluid from the train pipe, and means for venting air from said chamber and from the train pipe in making a service application of the brakes.

3. In a fluid pressure brake, the combination with a train pipe and a brake valve, of a valve for controlling the discharge of air from the train pipe, a movable abutment subject to the opposing pressures of the train pipe and a chamber or reservoir for operating said valve, and means controlled by said brake valve in making service applications of the brakes for venting air from said chamber and directly from the train pipe.

4. In a fluid pressure brake, the combination with. a train'pipeand a brake valve provided with an equalizing discharge valve mechanism operated by a reduction in pressure in a chamber or reservoir for releasing air from the train pipe, of a direct train pipe discharge port controlled by the brake valve for also releasing air from the train pipe in making a service application of the brakes.

5. In a fluid pressu'rebrake, the combination With a train pipe and a brake valve pro-.

vided with an equalizing discharge valve mechanism operated by reducing the pressure in a chamber or equalizing reservoir for discharging air from the train pipe, of a reducing reservoir into which air from the equalizing reservoir is vented for limiting the reduction in pressure therein, a direct train pipe discharge port for also releasing fluid from the train pipe and means for cutting off the flow of air through said direct discharge port upon equalization of the equalizing reservoir and reducing reservoir pressures.

6. In a fluid pressure brake, the combination with a train pipe and -a brake valve, of a valve mechanism subject to the opposing pressures of the train pipe and a chamber and operated by venting air from said chamber for releasing air from the train pipe and a closed receptacle for receiving the air vented from said chamber to limit the reduction in pressure therein to a predetermined amount, a direct port for releasing air from the train pipe and means governed by the pressure in said receptacle for controlling the release of air through said direct exhaust port.

In testimony whereof I have hereunto set my hand.

WALTER V. TURNER. \Vitnesses:

WM. M. OADY, A. M. CLEMnNTs.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. 

